Connector for high-rate transmission

ABSTRACT

A high speed transmission connector includes a base board side connector and a cable side connector to be connected with each other and a metal shell which covers a housing and contacts arranged in the housing. By inserting the metal shell of the cable side connector into the metal shell of the base board side connector, the contacts and the metal shells are respectively connected electrically. The metal shell of the base board connector includes a recess portion for adjusting a space between the metal shell and the contact in the base board side connector. With this invention, the characteristic impedance can be adjusted with an easy method and can sufficiently cope with the miniaturization of the connector and with a higher density.

FIELD OF THE INVENTION

The present invention relates to a high speed transmission connector inwhich an impedance matching function is given to a metal shell coveringa housing where a plurality of contacts are arranged.

BACKGROUND OF THE INVENTION

For a high speed transmission connector, particularly for a connector ora cable located on a transmission path of a differential signal, acharacteristic impedance matching is required, in addition to therequirement for a simple and easy inter-connection of the existingapparatus.

For example, in a connector for communication in an audio/visualapparatus, reduction of the number of connectors to be connected andminiaturization of the connector per se have been continuously required,and in addition, the following problem has arisen as a new requirementfor the connector in line with the new high speed digital transmission.That is, when there is an impedance mismatch in the connector portion, asignal of an image or sound is deformed or reflection occurs, and, as aresult, the image or sound cannot be properly reproduced. Therefore, insuch a connector to be inserted into a high frequency signaltransmission path, the matching performance of the impedance is also oneof the important requirements.

Japanese Patent Laid-Open Publication No. Hei 7-106027 discloses atechnology considering characteristic impedance of a connector. In thistechnology, a high frequency signal transmission path is realized by acontact having a non-coaxial structure and constructing a control signaltransfer path by also the same contact parts whereby the low cost andthe miniaturization may be attained.

In a recent signal transmission connector, the outside of a housingwhere contacts are arranged is covered with the metal shell. This isbecause, by covering the housing with the metal shell, the noise or lossdue to the generation of an electromagnetic wave radiation may beeffectively prevented.

In the case where this kind of connectors is a pair of connectors(composed of a male connector and a female connector) to be coupled witheach other, metal shells are provided, as an electromagnetic shield, forthe respective connectors. At the time of coupling, generally, the metalshell on one connector is inserted into the metal shell on the otherconnector so that the metal shells are electrically connected to eachother, thereby to place it in a mode where these potentials aremaintained at an equal level and the grounding is to be made.

The metal shells of the two connectors are formed into a sleeve-shapehaving an engaging portion for coupling with each other. Therefore,since the metal shell of one connector is inserted into the metal shellof the other connector, the metal shell and the connector placed thereinare inevitably most closed to each other. As a result, there arises aproblem of mismatch in impedance at the engaging portion.

In this respect, some conventional connectors adopted a method ofadjusting the characteristic impedance on the basis of a pitch of thecontacts, the width dimension of the contacts, or on the basis of aninduction rate of an insulator (housing) for holding the contacts.

However, with these methods, there are various drawbacks in designingand manufacturing the connectors, in that, for adjusting thecharacteristic impedance, the connector itself or its pitch is widened,thereby sacrificing the miniaturization and high density aspects of theconnector. In addition, for the contacts to be made of a plate material,it must be selected from materials having a thickness which is notgenerally available on the market.

OBJECT AND SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a high speedtransmission connector capable of easily adjusting the characteristicimpedance and of sufficiently coping with making the connectorminiaturized and having higher density.

The high speed transmission connector according to the present inventionis comprised of a pair of connectors (namely, a female connector and amale connector) to be coupled with each other; wherein each connector isprovided with a metal shell for covering a housing and contacts arrangedwithin the housing and the metal shell of one connector is inserted intothe metal shell of the other connector, thereby the metal shells as wellas the contacts are electrically connected, respectively, and a recessportion, such as the depression or dimple shown, is provided in themetal shell of one connector for adjusting an interval between thecontact and the metal shell of the other connector.

According to the present invention, since a recess portion is providedfor adjusting a space between the contact and the metal shell within oneconnector, it is possible to perform matching of the impedance by theaction of this recess portion. That is, the recess portion is notprovided by using a separate member but can be easily formed bypress-machining or embossing the metal shell. In addition, it is alsoeasy to adjust a depth of the recess portion. Therefore, it is possibleto easily adjust the impedance by means of this recess portion. This isbecause the impedance of the connector is changed greatly depending uponthe space between the metal shell and the contact.

It is preferable that the space between the contact and the recessportion in one of the connectors be set to be substantially equal to thespace between the contact and the metal shell in the other connector.Thus, with this structure, since the overall length of the space betweenthe contact and the metal shell in the connectors, after engagement witheach other, becomes substantially equal to each other, matching of theimpedance also becomes easy.

Here, the recess portion of the metal shell may be provided in plural.For the recess portion, a single large recess portion may be provided.However, in the case where, for example, the recess portion is formed bypress-machining, forming a plurality of recess portions is easier bypress-machining and easy to secure the mechanical strength of the metalshell. Further, in the case where the contacts are plural, the pluralityof recess portions may correspond to the plurality of contacts with highprecision.

It is preferable that in each connector a plurality of contacts arearranged at intervals in a widthwise direction of the connector. Byarranging the contacts in the widthwise direction of each connector, itis possible to attain the high density and, in addition, to easily makeeach contact correspond to the respective recess portions.

The recess portions are arranged with intervals in a direction of widthof the connector. With this arrangement, the plurality of recessportions can be formed in a rectangular shape or an oval shape withoutdifficulty and with a high density.

Also, it is preferable that each recess portion is provided in a plateportion of the metal shell of one connector adjacent to an engagingportion into which the other connector is inserted. With this structure,it is possible to avoid the adverse influence on the region of thecoupling portion of the connectors by the existence of the recessportion. That is, the bottom of the recess portion projects inwardlyfrom the inner surface of the metal shell but the recess portion isdisplaced from the region of the coupling portion of the connectors.Therefore, it is possible to obtain a structure that is good inattempting miniaturization and thinning of the connector having a higherdensity.

It is preferable that the recess portion is provided on the metal shell,which is in the vicinity, particularly above or below, of the contactwhich transmits a differential signal. With such structure, eachdifferential signal can be transmitted properly without degrading thequality of the signal.

At this time, a portion corresponding to the bottom of the recessprojecting inwardly may be made a stopping portion to which the metalshell of the other connector hits, thereby to precisely define anengagement position of the two connectors.

Further, locking means may be provided on the metal shell of either oneof the connectors or both connectors, so as to lock the connectors witheach other. This locking means assures the effect of the electricalconnection between the metal shells and to exhibit a locking function.

BRIEF DESCRIPTION OF THE DRAWINGS

The organization and manner of the structure and operation of theinvention, together with further objects and advantages thereof, maybest be understood by reference to the following description, taken inconnection with the accompanying drawings, wherein like referencenumerals identify like elements in which:

FIG. 1 is a cross-sectional view of the essential portions of aconnector on the side of a base board and a connector on the side of acable according to a first embodiment of the present invention, whereinthe upper and the lower contacts are schematically shown in the samecross-sectional view;

FIG. 2 is a perspective view of the connector on the side of the baseboard according to the first embodiment of the present invention;

FIG. 3 is a cross-sectional view of the connector on the side of thebase board according to the first embodiment of the present invention,showing only the upper side contact;

FIG. 4 is a front view of the connector on the side of the base boardaccording to the first embodiment of the present invention;

FIG. 5 is a plan view of the connector on the side of the base boardaccording to the first embodiment of the present invention;

FIG. 6 is a side view of the connector on the side of the base boardaccording to the first embodiment of the present invention;

FIG. 7 is a front view of the connector on the side of the base boardaccording to a second embodiment of this invention; and

FIG. 8 is a partial sectional view of the connector on the side of thecable according to each embodiment of this invention.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

While the invention may be susceptible to embodiment in different forms,there is shown in the drawings, and herein will be described in detail,a specific embodiment with the understanding that the present disclosureis to be considered an exemplification of the principles of theinvention, and is not intended to limit the invention to that asillustrated and described herein.

An embodiment in which the present invention is applied to a high speedtransmission connector of a portable communication device will bedescribed below. FIG. 1 is a cross-sectional view showing, for theconvenience sake, the essential portions of connectors according to afirst embodiment of the present invention. FIG. 2 is a perspective viewof a connector mounted on a print base board (hereinafter referred tosimply as “the base board side connector”) of the first embodiment. FIG.3 is a cross-sectional view of the connector.

Namely, in a general view, the connection as shown in FIG. 1 isaccomplished by connecting a connector for a differential transmissioncable (hereinafter referred to simply as “the cable side connector”)shown in FIG. 8 to the connector mounted on the base board shown in FIG.2 and FIG. 3. Details will be described below.

The high speed transmission connector in accordance with this embodimentincludes a base board side connector 10 and a cable side connector 20which are connected with each other. Each connector 10, 20 includes acontact 12, 22 disposed within a housing 11, 21 and a metal shell 13, 23for covering the housing 11, 21.

As shown in FIG. 1, the connector 10 mounted on the base board includesthe housing 11 made of an insulating resin, a plurality of contacts 12provided in the housing 11 by a pressure fitting or an insert molding,and a metal shell 13 provided so as to cover the outside of the housing11 except for an opening portion 14.

The opening portion 14, which is an engaging portion, is provided at oneend of the housing 11 as shown in FIG. 2, into which the cable sideconnector 20 is inserted and engaged. That is, a hollow portion 14A isformed inside the opening portion 14, and into this hollow portion, anengaging portion 23 c of the cable side connector 20 and further thecontact 22 provided inside the engaging portion 23 c are inserted.

At the center portion in the hollow portion 14A, a plate shape contactsupport 15 is projected toward the opening portion 14.

Each contact 12 is mounted in such manner that a part thereof isembedded in the upper surface and the lower surface of the contactsupport 15. That is, each contact 12 is provided on the top and thebottom of the contact support portion 15 and arranged with a spacebetween the adjacent contacts in a widthwise direction (in a directionindicated by an arrow A in FIG. 2) of the base board side connector 10.

Further, each contact 12 is arranged with a displacement by a half pitchbetween on the top surface and the bottom surface of the contact support15. With this arrangement, tails 12 a can be arranged in a single rowwith high density, thereby to provide a desirable base board mountedconnector which does not consume an area on the base board for surfacemount. (For the sake of convenience for describing the embodiment ofthis invention, the top and the bottom contacts 12 and 22 are shown onthe same vertical section in FIG. 1 and FIG. 8.)

In theses contacts 12, although depending on the usage of contact, thenumber of poles in the transmission path, and the like, generally, theground contacts and the signal contacts that form the transmission pathof the high frequency signal are so arranged to be adjacent to oneanother in use.

As shown in FIG. 1, the metal shell 23 of the cable side connector 20 isinserted into the metal shell 13 of the base board side connector 10 sothat the metal shells 13, 23 and the contacts 12, 22 are electricallyconnected to each other, respectively.

As shown in FIG. 8, the cable side connector 20 has, within the forwardend portion thereof, the contact 22 comprises a spring member, therebythe housing 21 is surrounded by the metal shell 23.

The connector according to this embodiment has a remarkable feature inthat a recess portion 16, such as the depression or dimple shown, isprovided in plural in the metal shell 13 of the base board sideconnector 10, for adjusting the space between metal shell 13 and thecontacts 12 in the base board side connector 10.

The reason why the recess portions 16 are provided is to attemptmatching of the impedance by the effect of these recess portions 16.Here, the recess portions 16 are formed by a press-machining (embossing)of the metal shell 13. In the case of the press-machining, the depth ofthe recess portions 16 may easily be adjusted. Therefore, it is possibleto adjust the impedance by these recess portions 16 with ease. Thereason for this is that the impedance of the base board side connector10 changes greatly by a space between the metal shell 13 and the contact12.

With the embodiment shown in FIG. 1, the space between the contact 12and the recess portion 16 in the base board side connector 10 is set tobe substantially equal to the portion where the cable side connector 20is inserted and its metal shell 23 is lying over an inner surface of themetal shell 13. That is, as shown in FIG. 1, the inner surface (theinner surface just below the recess portion 16) 16 a corresponding tothe recess portion 16 of the metal shell 13 and an inner surface 23 a ofthe metal shell 23 of the cable side connector 20 are so set insubstantially the same plane.

As a result, the respective spaces between the contact 12 and the metalshells 13, 23 become substantially equal to one another through thewhole length of the base board side connector 10 and the cable sideconnector 20, thereby the impedance in this portion is matched with eachother.

As shown in FIG. 2, the recess portion 16 of the metal shell 13 of thebase board side connector 10 is provided in plural. Of course, a singlelarge recess portion may be provided as the recess portion 16. However,in the case where, for example, the recess portion 16 is formed by thepress-machining, it is advantageous to form a plurality of recessportions because the press-machining is facilitated and the mechanicalstrength of the metal shell 13 may be easily secured. Further, in thecase of the plurality of contacts 12 are provided, the plurality ofrecess portions can be set to correspond to the respective contacts withhigh precision.

The contact 12 of the base board side connector 10 is provided in pluraland they are arranged with a space between the adjacent contacts in thewidthwise direction of the base board side connector 10. By arrangingthe contacts 12 in the widthwise direction of the base board sideconnector 10, not only the high density is obtained, but also tofacilitate the respective contacts 12 to correspond to the respectiverecess portions 16.

The respective recess portions 16 are in the form of a flat rectangularshape and, in this embodiment, four recess portions are provided with aspace between the adjacent recess portions in the widthwise direction ofthe base board side connector 10. Thus, it is possible to arrange therespective recess portions 16 with respect to the metal shell 13 at ahigh density without difficulty.

Next, a second embodiment will be described based on FIG. 7. In theabove-described first embodiment, the respective recess portions 16 areprovided in an upper surface 13 f of the metal shell 13, but in thesecond embodiment, the recess portions are provided in both the uppersurface 13 f and a lower surface 13 b. This arrangement is to preventdegradation of signals in a more preferable mode based on thearrangement of differential signals.

Throughout the two embodiments, the recess portions 16 are providedadjacent to the opening portion 14 where the cable side connector 20 isinserted and engaged. With this structure, it is possible to avoid theadverse influence on the region C of the coupling portion of theconnectors by the existence of the recess portions 16. That is, therecess portion 16 projects from the inner surface 13 a of the metalshell 13 but is displaced from the region C of the coupling portion ofthe connectors. Therefore, it is possible to obtain a structure that isgood in attempting miniaturization and thinning of the connector withhigher density.

As can be understood from FIG. 1, the forward end of the metal shell 23of the cable side connector 20 may be formed, by utilizing the projectedbottom portion of the recess portion 16, to be a stopper with which theengaging portion 23 c is brought into contact, thereby the engagingposition for the two connectors can be defined.

In order to ensure the electrical connection of the metal shells 13, 23with each other, an engagement piece 18 is provided on the metal shell13 of the base board side connector 10 for engaging with the metal shell23 of the cable side connector 20. This engagement piece 18 can exhibita locking function in addition to an effect to ensure the electricalconnection of the metal shell 13, 23 with each other.

This locking function is constructed of a convex portion 18 a providedin the engagement piece 18, and an engagement hole 23 b provided in themetal shell 23 of the cable side connector 20 such that the convexportion 18 a can be engaged. The locking functions may be provided inplural as required.

With the high speed transmission connector according to the presentinvention, it is possible to adjust the characteristic impedance throughan easy method and also to cope sufficiently with the miniaturization ofthe connector and making it with a higher density. In particular, sincethe recess portion is provided for adjusting a space between the contactand the metal shell within one connector, it is possible to match theimpedance by the effect of this recess portion. That is, the recessportion is provided not by a separate member, but may be easily formedin a desired size by a press-machining the metal shell or the like. Inaddition, it is easy to adjust a depth of the recess portion. Therefore,it is easy to adjust the impedance by means of this recess portion.

While a preferred embodiment of the present invention is shown anddescribed, it is envisioned that those skilled in the art may devisevarious modifications of the present invention without departing fromthe spirit and scope of the appended claims.

1. A high speed transmission connector assembly comprising: a pair ofconnectors to be connected with each other, each connector including ahousing and a metal shell which covers the housing and a contactarranged in the housing, wherein the metal shell of one connector isinserted into the metal shell of the other connector thereby toelectrically connect the metal shells and the contacts respectively; anda recess portion is provided on the metal shell of one connector, foradjusting a space between the contact in said connector and the metalshell.
 2. The high speed transmission connector assembly according toclaim 1, wherein the space between the contact and the recess portion insaid one connector is set to be substantially equal to a space betweenthe contact and the metal shell in said other connector.
 3. The highspeed transmission connector assembly according to claim 1, wherein therecess portion is provided in plural.
 4. The high speed transmissionconnector assembly according to claim 1, wherein the contact of said oneconnector is provided in plural with a space between the adjacentcontacts in a widthwise direction of the connector.
 5. The high speedtransmission connector assembly according to claim 3, wherein eachrecess portion is provided with a space between adjacent recess portionsin the widthwise direction of the connector.
 6. The high speedtransmission connector assembly according to claim 1, wherein eachrecess portion is provided in a flat portion of the metal shell andwhich is adjacent to an engaging portion into which the other connectoris inserted.
 7. The high speed transmission connector assembly accordingto claim 1, wherein the recess portion is provided in the vicinity ofthe contact for transmitting a differential signal.
 8. The high speedtransmission connector assembly according to claim 1, wherein eachrecess portion serves as a stopper at which a tip of the metal shell isbrought into contact with the inner surface of one connector when theother connector is inserted thereinto.
 9. The high speed transmissionconnector according to claim 1, wherein engaging means is provided oneither one of the metal shell of one connector and the metal shell ofthe other connector, or on both metal shells, for connecting thereof.10. A high speed transmission connector capable of being mated to amating connector having a housing and at least one contact arranged inthe housing, the high speed transmission connector comprising: ahousing, a metal shell which covers at least a portion of the housingand a contact arranged in the housing, wherein the metal shell of thehigh speed transmission connector is inserted into the metal shell ofthe mating connector to electrically connect the metal shells and thecontacts respectively; and a recess portion provided on the metal shellof the high speed transmission connector for adjusting a space betweenthe contact in said high speed connector and the metal shell.
 11. Thehigh speed transmission connector according to claim 10, wherein thespace between the contact and the recess portion in said high speedtransmission connector is set to be substantially equal to a spacebetween the contact and the metal shell in said mating connector. 12.The high speed transmission connector according to claim 10, wherein therecess portion is provided in plural.
 13. The high speed transmissionconnector according to claim 10, wherein the contact of said high speedtransmission connector is provided in plural with a space between theadjacent contacts in a widthwise direction of the high speedtransmission connector.
 14. The high speed transmission connectoraccording to claim 12, wherein each recess portion is provided with aspace between adjacent recess portions in the widthwise direction of thehigh speed transmission connector.
 15. The high speed transmissionconnector according to claim 10, wherein each recess portion is providedin a flat portion of the metal shell and which is adjacent to anengaging portion into which the mating connector is inserted.
 16. Thehigh speed transmission connector according to claim 10, wherein therecess portion is provided in the vicinity of the contact fortransmitting a differential signal.
 17. The high speed transmissionconnector according to claims 10, wherein each recess portion serves asa stopper at which a tip of the metal shell is brought into contact withthe inner surface of the high speed transmission connector when themating connector is inserted thereinto.
 18. The high speed transmissionconnector according to claim 10, wherein engaging means is provided oneither one of the metal shell of the high speed transmission connectorand the metal shell of the mating connector, or on both metal shells,for connecting thereof.
 19. A receptacle connector for mating to anopposing plug connector, the opposing plug connector having aninsulative housing supporting a plurality of terminals and an outerconductive shell, the receptacle connector comprising: an insulativehousing supporting a plurality of terminals, the plurality of terminalsincluding at least one pair of differential signal terminals, saidterminals each including contact portions and tail portions and bodyportions that interconnect said contact and tai portions together; aconductive outer, hollow shell that at least partially encloses thehousing and said terminals and defines a hollow receptacle into whichthe opposing plug connector may be inserted so that an outer surface ofsaid opposing plug connector outer shell abuts an inner surface of saidreceptacle connector outer shell, the terminal contact portions beingdisposed within the receptacle connector outer and the terminal bodyportions being supported by said housing within said shell; said shellincluding at least one depression formed therein in opposition to saidhousing and the depression being further aligned with a body portion ofat least one of said differential signal terminals, said depressionhaving a front edge proximate to a front edge of said housing, thedepression front edge forming a stop surface against which a leadingedge of said opposing plug connector outer shell abuts when saidopposing plug connector outer shell is fully inserted into saidreceptacle connector.
 20. The receptacle connector of claim 19, whereinsaid depression is formed as a dimple in said shell.
 21. The receptacleconnector of claim 20, wherein said dimple has a body portion that iscollinear with said opposing plug connector outer shell.
 22. Thereceptacle connector of claim 20, wherein said dimple has a body portionand said receptacle connector outer shell has a first inner surface thatis spaced apart from said terminal contact portions a first distance andsaid dimple defines a second inner surface of said receptacle connectorouter shell, different than the receptacle connector outer shell firstinner surface, the receptacle connector outer shell second inner surfacebeing spaced closer to said terminal body portions than said receptacleconnector outer shell first inner surface is spaced from said terminalcontact portions.
 23. The receptacle connector of claim 22, wherein saiddimple extends over said body portions of said differential signalterminals.
 24. The receptacle connector of claim 22, wherein said dimpleis rectangular in configuration.